[ale] Questions on SSH tunnel setup for 'tightvnc'

[Joe Knapka]

John Mills <johnmills at speakeasy.net> writes:

> Joe -
> 
> Thanks for the comments. Naturally they brought me to the next plateau of 
> ignorance.
> 
> On 24 Jan 2004, Joe Knapka wrote:
> 
> > John Mills <johnmills at speakeasy.net> writes:
>  
> > > Q3. Do I need to start any task in host's rc.local to activate the xdm 
> > > login on <host_vnc_port>?
> 
> > [Re: the xinetd approach] ... I haven't ever actually done that;
> > explicitly starting a VNC session in rc.local works for me. The nice
> > thing about doing it via inetd is that you can have any number of VNC
> > clients connected at the same port, to different server instances (I
> > believe).
> 
> Could you elaborate a bit here? What do you put in rc.local?

Something like

su -l joe -c vncserver :1

which starts a VNC server listening on port 5901. Since I'm the only
person who ever uses the machine, a single dedicated server is all I
need.

> Is a VNC 
> password used?

Yes, but I have to configure it manually via "vncpasswd" from a shell
prompt, sometime before adding the VNC line to rc.local.

> Is there an implicit or explicit user at that stage? (It 
> sounds as though you connect to a login screen, which is what I would 
> want.)

No, I connect to the already-running server. The only security is the
VNC password prompt (FWIW - if I'm going across the net I tunnel via
SSH, of course).  Remember that the X VNC server is just an X server
(in fact, it's XFree86 with all the graphics hardware support ripped
out and replaced with an RFB codec), so you have to configure it in
essentially the same way you do a regular X session: via a shell
script. If you start a VNC server as yourself, it reads and executes
the file ~/.vnc/xstartup; my version has a single line:

exec fvwm

which starts the fvwm window manager, so I end up looking at an
fvwm session rather than a blank screen with the "X" cursor.

> When I use the xinetd approach I just get a "dumb" X-session (tiled
> window, cursor, no apps running - not even the xdm login). I haven't
> figured out how to get any other response at that point.

There's certainly a way to make this happen, but as I said, I've never
done it.  It probably involves pointing inetd not at "vncserver", but
rather at a script that starts vncserver and then does some other
stuff to configure the X session properly (eg running xdm or
whatever on the display associated with the new server instance).

Or perhaps I'm wrong. This page
<http://www.dei.isep.ipp.pt/~andre/extern/ixvnc.htm> (by the author of
the original -inetd patch to XVNC) seems to suggest that a properly
configured [X|G|K]DM server will provide login screens for VNC
sessions by magic. I think reading that page might help you.

HTH,

-- Joe Knapka

-- 
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